Physicochemical Properties of Biscuits Enriched with Horseradish (Armoracia rusticana L.) Products and Bioaccessibility of Phenolics after Simulated Human Digestion

Health-conscious consumers are interested in products with an increased bioactive compound content. The nutritional quality is considered both as a stability and bioaccessibility concern. The aim of this study was to investigate the effect of horseradish products (horseradish root pomace, horseradish leaf pomace, microencapsulated horseradish root and leaf juice) on the physicochemical properties of biscuits, as well as to assess in vitro bioavailability and activity of phenolics. The bioactive compounds and antioxidant activity of horseradish products, which were used to replace the flour in biscuit dough, were analysed. Physicochemical parameters (pH, water activity, colour, phenolic compound contents, and antioxidant activities) were determined for the biscuits. Horseradish products compared to other cruciferous vegetables have a high content of phenolic compounds, as well as high antioxidant activity. Higher levels of bioactive compounds were found in microencapsulated horseradish leaf juice, compared to the other horseradish products used in the study. Enriched biscuits had a significantly higher total phenolic content (TPC) and antioxidant activity, compared to the control. After 180-day storage, TPC of biscuits with horseradish root products did not change significantly but in biscuits with horseradish leaf products it decreased by 27–29%. The bioaccessibility index of phenolic compounds after in vitro digestion of enriched biscuits ranged between 2.19 and 2.99. Microencapsulated horseradish leaf juice was more effective in enriching biscuits with bioactive compounds. The developed biscuits enriched with horseradish products could meet consumer expectations for healthy, functional food.